This invention generally relates to an agitator designed to continuously move powdered material into flights of a metering auger of a volumetric metering apparatus using vanes at various radii within a hopper. 2. Description of Related Art
Powdered material, such as toner, is packaged according to net weight, but is filled volumetrically. This is accomplished using a metering auger located at the bottom of a hopper. The metering auger turns a specific number of times, regardless of whether there is material flowing through it, dispensing a predetermined amount of material. This auger rotates at a high rate of speed, between 300-1000 rpm for dispensing toner particles. This high speed tends to draw more material out of the area around the auger than may be supplied by a conventional lower agitator or stirrer, rotating around the widest radius within the hopper.
This condition causes occasional starving of the metering auger, supplying an insufficient amount of material to the auger. Starving of the auger causes notable, and uncontrollable, variations in the amount of product delivered to the package. To accommodate this, slight overfilling of the package has been customary, ensuring that consumers receive at least a minimum stated amount of filled product. This negates an amount that may have been starved in the auger during metering.
in the previous known apparatus, there was typically between a 3-5 gram standard deviation per bottle filled. Considering the large number of toner bottle filled each year, this deviation has resulted in large amounts of excess toner being given away, at a large cost to the manufacturer.
This known apparatus, shown in FIG. 1, is not highly desirous because of the inaccuracy of the metered material. Additionally, the starved condition reduces the line rate of packages being filled.
There is a need for a more accurate volumetric metering apparatus that can be inexpensively manufactured and operated. There also is a need for improved line feed rate of packages being filled.
There are known dispensing apparatus, dispensing based on weight, that have better accuracy than the known volumetric apparatus. However, these require completely different equipment and usually are much higher in cost than traditional volumetric dispensing apparatus.